pISSN 2384-1095 iMRI 2016;20:200-205 http://dx.doi.org/10.13104/imri.2016.20.3.200 eISSN 2384-1109

En Plaque Tuberculoma: a Case Report

Young-eun Kim, Donghoon Lee, Hokyeong Hwang, Minji Kim Department of Radiology, Seoul Medical Center, Seoul, Korea

In Korea, is still common disease. Central nervous system tuberculosis can manifest in a variety of forms, including tuberculous meningitis, tuberculous cerebritis, tuberculoma, tuberculous abscess, and miliary tuberculosis. Although intra-axial tuberculomas are the more common type of CNS tuberculosis, extra- axial lesions are rarely encountered. En plaque tuberculoma is an extremely rare presentation of intracranial tuberculosis with mimicking primary or secondary meningeal neoplasia. We describe a rare case of an en plaque tuberculoma accompanied by tuberculous meningitis and tuberculomas. Case Report Keywords: En plaque tuberculoma; CNS tuberculosis; Magnetic resonance imaging

Received: August 13, 2016 Revised: September 13, 2016 Accepted: September 13, 2016 INTRODUCTION

Correspondence to: In Korea, tuberculosis (TB) remains a serious public health problem and reported TB Donghoon Lee, M.D. cases have not significantly decreased over the last decade (1). Tuberculosis involving Department of Radiology, Seoul Medical Center, 156 Sinnae- the central nervous system (CNS) is the most significant type of extrapulmonary ro, Jungnang-gu, Seoul 02053, tuberculosis because of its high mortality rate and possible morbidity of neurologic Korea. sequelae. CNS tuberculosis can manifest in a variable forms, including tuberculous Tel. +82-2-2276-7000 meningitis, tuberculous cerebritis, tuberculoma, tuberculous abscess, and miliary Fax. +82-2-2276-7093 tuberculosis (2). Although intra-axial tuberculomas are the more common type of CNS Email: [email protected] tuberculosis, extra-axial lesions are rarely encountered (3). Here, we report a rare case of an en plaque tuberculoma.

CASE REPORT This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License A 73-year-old woman visited the emergency department with mental change and (http://creativecommons.org/licenses/ vomiting. She had a past medical history of hypertension. Two days prior, she presented by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and with a headache, dizziness and drowsy mental status which were slowly progressing. reproduction in any medium, provided She complained of febrile sensation, and body temperature was 36.9°C. A cerebrospinal the original work is properly cited. fluid (CSF) analysis revealed WBC count of 520/µℓ (normal range, 0-4/µℓ) with lymphocyte dominance (90%), an adenosine deaminase (ADA) level of 24.3 IU/L (normal range, 0-8 IU/L), a total protein of 204.2 mg/dL (normal range, 15-45 mg/dL) and a glucose of 44 mg/dL (normal range, 40-75 mg/dL). Copyright © 2016 Korean Society A brain computed tomography (CT) scan showed multifocal low and suspicious of Magnetic Resonance in Medicine (KSMRM) isodensity lesions in the right medial frontal and left temporal lobes and a suspicious iso to high density lesion in the left temporal extra-axial space (Fig. 1a). On diffusion weighted imaging (DWI) of the brain (Magnetom Avanto 1.5T, Siemens,

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d e f Fig. 1. A 73-year-old woman with an en plaque tuberculoma. (a) CT scan showed iso to hyperattenuating lesion at left temporal extra-axial space with low density area in the Lt. temporal lobe. (b) DWI showed iso to low signal intensity lesion at left temporal extra-axial space. (c) T2-weighted axial MRI showed iso-signal intensity lesion with perilesional high signal intensity. (d-f) T1-weighted axial (d) MRI showed iso-signal intensity lesion with contrast-enhanced T1-weighted axial (e) and coronal (f) MRI showing homogeneous enhancing dural-based lesion in the left temporal convexity (arrows).

Erlangen, Germany), a lesion with iso to low signal intensity signal intensity (Fig. 1c, d). In addition, multiple ring and was observed in the left temporal convexity, as compared nodular enhancing lesions were observed in the cortico- with brain parenchyma (Fig. 1b). sulcal area of the right medial frontoparietal lobe and the Magnetic resonance imaging (MRI) obtained on a 3.0T left paramedian cerebellum. Some of these showed dark system (Achieva, Philips Healthcare, Best, The Netherlands) signal intensity on susceptibility weighted images (SWI) (Fig. by hospital day 1. A diffuse dural-based enhancing lesion 2). of about 4 cm in length was located mainly in the left By hospital day 1, the patient presented with a fever temporal convexity on contrast enhanced T1-weighted (38.0°C) and anti-tuberculosis therapy was initiated with images (T1WI) (Fig. 1e, f). The lesion showed iso signal HERZ (, rifampin, ethambutol, and ) intensity to the brain parenchyma on T1WI and T2- regimens, in combination with tapering doses of steroids weighted images (T2WI) with marked perilesional T2 high (dexamethasone) for 4 weeks. Although there was www.i-mri.org 201 En Plaque Tuberculoma | Young-eun Kim, et al.

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c d Fig. 2. Contrast-enhanced T1-weighted axial (a) and coronal (b) MRI showed multiple ring and nodular enhancing lesions in the cortico-sulcal area of the right medial frontoparietal lobe and left paramedian cerebellum (c). Some of these showed dark signal intensity on SWI (d). no evidence of pulmonary tuberculosis on her chest DISCUSSION radiography and CT scan, the result of a sputum acid-fast bacilli (AFB) culture confirmed the presence of tuberculosis According to the 2015 TB notification data, there were on hospital day 13. 32,181 reported cases of TB (63.2 cases per 100,000 people) By hospital day 28, a follow-up MRI demonstrated a in Korea. Of these, 6631 cases were extrapulmonary TB (13.0 marked decrease in size of the plaque-like enhancing cases per 100,000) which comprised 20.6% of all cases of mass lesion in the left temporal convexity (Fig. 3a, b). Also, TB. Among extrapulmonary TB, CNS TB was reported in 385 previously noted multiple tuberculomas in the right high cases (4). CNS tuberculosis can manifest in a variable forms, frontoparietal cortico-sulcal area and left paramedian including tuberculous meningitis, tuberculous cerebritis, cerebellum, showed a marked decrease in size and number, tuberculoma, tuberculous abscess, and miliary tuberculosis. as compared to the last MRI (Fig. 3c, d). The patient showed Although intra-axial tuberculomas are the more common an improvement in clinical status at the time of discharge type of CNS tuberculosis, extra-axial lesions are rarely after hospital day 28. encountered (3). An en plaque tuberculoma is a rare entity, first reported

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c d Fig. 3. Follow-up MRI (4 weeks later) contrast-enhanced T1-weighted axial (a) and coronal (b) MRI, showed a marked decrease in the extent of the plaque-like enhancing mass of the left temporal subdural space (arrows). Also multiple tuberculomas in the right high frontoparietal cortico-sulcal area (c) and left paramedian cerebellum (d), showed a marked decrease in size and number on contrast-enhanced T1-weighted axial MRI. in 1927, commonly described as a plaque-like meningitic progressive (5, 6). process without exudation (5). CNS tuberculosis usually Radiologic features of en plaque tuberculomas include results from hematogenous spread. However, it may result appearing hyperdense on noncontrast CT scans, isointense from direct invasion or rupture of a subependymal or to the brain on T1WI, and isointense to hypointense to subpial Rich focus. These CNS tuberculosis lesions may the brain on T2WI with homogeneous post-contrast be located in the meninges, brain, or spinal cord (2). Also, enhancement (6, 7). However, Srikanteswara et al. (6) when the meningeal inflammation is confined, it forms a reported various enhancement patterns of en plaque macroscopically hard fibrous mass that is attached to the tuberculomas including a thin peripheral, homogeneous, dura without calcification or caseation, and is situated varied enhancement and an open ring enhancement. Most deep in a sulcus in relation to the meninges. The hard of the lesions are associated with perilesional edema (5). fibrous mass is considered to be a likely source of diffuse The location of the en plaque tuberculoma is described meningitis and is the result of bacillemia that occurs during as variable including the frontal and parietal convexities, the development of the primary lesion or after primary interhemispheric fissure, tentorium cerebelli and posterior www.i-mri.org 203 En Plaque Tuberculoma | Young-eun Kim, et al. fossa (6). However, similar imaging findings can be seen complete blood cell count were within normal limit. And in various cases of inflammatory and non-inflammatory intracranial and extra-axial lesions were improved on a conditions, showing dural-based lesions, the most common follow up MRI study after administering anti-tuberculosis being meningiomas (5, 7). Khanna et al. (3) reported a therapy. The en plaque tuberculoma responds well to anti- case of MR spectroscopy findings of giant extra-axial tuberculosis therapy (7). These findings help to establish tuberculoma. In this case, the extra-axial tuberculoma the diagnosis of CNS tuberculosis without biopsy and showed high lipid-lactate peaks and a decrease in N-acetyl pathologic confirmation. aspartate (NAA)/creatinine (Cr) and NAA/choline ratios Anti-tuberculosis therapy constitutes the mainstay of which differ from meningioma with an elevation of alanine treatment for CNS tuberculosis. The regimen is usually (Ala). The differing MR spectroscopy pattern and presence continued for 12-30 months (5, 10). Early treatment with of perilesional edema are among the few points that help steroids is recommended in patients with TB meningitis in in differentiating it from meningiomas (5). Srikanteswara a dose of 0.4 mg/kg/day for 1-2 weeks and tapered over et al. (6) reported that a follow-up MRI study performed the next few weeks with monitoring regardless of severity 6 months after initiation of anti-tuberculosis therapy in 5 in order to significantly decrease the risk of mortality and patients showed a disappearance of the lesion as well as of reduce neurological sequelae (5, 9). the meningeal enhancement. In conclusion, we report a rare case of an en plaque Alkan et al. (8) reported a case of the en plaque tuberculoma that presented as hyperdense on nonenhanced tuberculomas of tentorium in a pregnant woman. She had CT scans, isointense to the brain on T1WI, and isointense to en plaque tuberculoma in the right tentorium with multiple hypointense to the brain on T2WI with homogeneous post- intra-axial ring-like enhanced tuberculomas on contrast contrast enhancement. Awareness of these characteristics enhanced T1WI. The rest of pregnancy was without problem will allow early diagnosis and optimal management of en and a healthy child was born by vaginal delivery. After 8 plaque tuberculomas. months of anti-tuberculosis therapy, follow-up MRI showed disappearance and improvement of the tuberculomas. Patients with extracranial tuberculosis usually present REFERENCES with focal neurologic deficits and seizures in the absence of 1. Kwon YS, Koh WJ. Diagnosis of pulmonary tuberculosis increased intracranial pressure (5). 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